Prime Lime. This brighly acid tropical green stone is most common where it's anything but balmy: Siberia.The chromium in the mineral's name is the same element that gives emerald their deeper green hue, which is why it's sometimes called the "Russian Emerald." One important difference: price. Chrome Diopside offers an affordable alternative to pricier green gems, and it's a natural for anyone who loves gardens. But don't wear it when weed-whacking, since it's a comparatively soft stone on the Mohs Hardness Scale. Gemstone Details